摘要
多普勒中心估计一般使用原始数据或距离压缩后的数据,但目前缺少统一的参数对估计精度进行分析。在多普勒模糊数准确的前提下,提出了根据几何模型和多普勒中心精度要求划分数据块,利用多普勒中心估计值的距离梯度均值和标准差分析多普勒中心的方法。实验表明,利用原始数据得到的多普勒中心估计值其距离梯度的均值和标准差都小于几何模型限定值,利用距离压缩后数据得到的多普勒中心估计值其距离梯度的均值和标准差都大于几何模型限定值,同时通过对多普勒中心估计值进行距离向二次拟合,剔除了大于几何模型限定条件的估计值。综上所述,利用距离梯度有效对估计值精度进行了分析。
The raw data or range compressed data is used during doppler centroid estimation commonly,but it lacks the uniform parameter to analyze the accuracy of the doppler centroid.A method is presented that it divides the data blocks based on the geometry model and doppler centroid accuracy requirement and analyzes the doppler centroid by mean and standard deviation of the doppler centroid gradients in the range.The correct doppler ambiguity is assumed.The experiments show that mean and standard deviation of the doppler centroid gradients in the range gained by the raw data are smaller than the geometry model limit,while mean and standard deviation of the doppler centroid gradients are larger than the geometry model limit when the range compressed data is used.Meanwhile,the doppler centroid is fitted by polynomial versus the range,and the estimated results whose range gradients are larger than the geometry model limit are eliminated.In conclusion,the mean and standard deviation of range gradients are effective to analyze the accuracy of the doppler centroid.
出处
《航天返回与遥感》
2011年第3期57-61,共5页
Spacecraft Recovery & Remote Sensing
基金
国家重大科技专项工程
关键词
多普勒中心估计
距离梯度
精度分析
几何模型
Doppler centroid estimation Range gradient Accuracy analysis Geometry model
